Hydrocyclone

Hydrocyclone uses centrifugal force to speed up the sedimentation of ores. The feeding needs pressure so the machine consumes much energy. But it covers a small floor space with low price, large capacity and high efficiency of classification. It’s used to separate coarse particles in the sewage or dewater the slurry sometimes. It has separate pressure and gravity types, commonly adopting column structure or metal tube. Water enters into the upper of the structure (or metal tube) along the tangent by pressure or gravity. Coarse particles are thrown and discharged with strong liquor under the centrifugal force. Smaller particles will be discharged with the secondary upward vortex.

Suspension liquid enters into the hydrocyclone from the feeding tube along the direction of the tangent at a high speed. Limited by the outer drum wall, the liquid is forced to revolve from the top to the bottom, which is commonly called as outer cyclone or decreased cyclone movement. The larger the density of solid particles than that of the surrounding liquid (mostly) is, the larger the centrifugal force is. Once this force exceeds the liquid resistance, solid particles will move toward the wall by overcoming it and separate with the suspension liquid. Particles near the wall will be pushed down ward to form dense suspension liquid near the underflow outlet and then be discharged. Purified liquid (including some small particles) will move downward spirally. After entering into the cone, the rotary speed is faster when the inner diameter of the separator becomes smaller. Because of the unevenness of pressure, it’s smaller as it gets closer to the axle with zero in the axle, which becomes low pressure zone or even vacuum area. Thus, it leads liquid to moving toward the axle. Meanwhile, the liquid cannot be discharged quickly because the outlet is greatly reduced. Some liquid will move toward the overflow outlet in the center top of the cyclone chamber because it’s at the low pressure zone. Therefore, upward cyclone movement is formed and the liquid can be discharged.